Asolid is a substance a. that has a fixed shape and volume. b. that is invisible. c. that has a changing shape and volume. d. that has no shape or volume.

Fixed shape and fixed volume

Explanation:

The first answer is correct I did this on odyssey and the answers are both fixed.

one is through turgidity. this occurs before ground tissue ( collenchyma

and sclerenchyma cells) become well

developed to give structural support to the plant as it grows bigger. the xylem

tissue (composed of rigid tissue) of the young

plant render this support and also maintaining osmotic turgidity of the surrounding

plant cells.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".